1. Field of the Invention
The present invention relates to an image reader that reads an image on an imaging target medium.
2. Description of the Related Art
An image reader that reads or scans an image recorded on an original (imaging target medium) has been developed. Examples of image readers are disclosed in Japanese Patent No. 3227231, Japanese Patent No. 3292392, and Japanese Patent Application Laid-open No. H11-205538.
In the existing image readers disclosed earlier, if a visible light, which is a light of a wavelength inside a visible spectrum, irradiating an original and an image of a reflected light, which is based on the visible light, of the wavelength inside the visible spectrum, is picked up by a first imaging unit, image data picked-up by the first imaging unit based on the light of the wavelength inside the visible spectrum is generated. Moreover, if a light such as an ultraviolet light of a wavelength outside the visible spectrum irradiates the original and an image of a reflected light, which is based on the light such as the ultraviolet light, of the wavelength outside the visible spectrum is picked up by a second imaging unit, image data picked-up by the second imaging unit based on the light of the wavelength outside the visible spectrum is generated. Thus, the picked-up image data that is based on the light of the wavelength inside the visible spectrum and the picked-up image data that is based on the light of the wavelength outside the visible spectrum can be generated.
However, in the existing image readers disclosed earlier, for generating the picked-up image data that is based on the light of the wavelength inside the visible spectrum and the picked-up image data that is based on the light of the wavelength outside the visible spectrum, an imaging target portion of the original needs to be reciprocated along a vertical scanning direction. In the existing image readers disclosed earlier, for example, the visible light needs to irradiate the original while moving the imaging target portion, of the original, that is captured as an image by the imaging unit in an outward direction along the vertical scanning direction and the picked-up image data, based on the light of the wavelength inside the visible spectrum, needs to be generated by using the resulting reflected light. Furthermore, the ultraviolet light needs to irradiate the original while moving the imaging target position of the original in a homeward direction along the vertical scanning direction and the picked-up image data, based on the light of the wavelength outside the visible spectrum, needs to be generated by using the resulting reflected light. Thus, for generating the picked-up image data that is based on the light of the wavelength inside the visible spectrum and the picked-up image data that is based on the light of the wavelength outside the visible spectrum from the original, the imaging target portion of the original needs to be moved (scanned) along the vertical scanning direction for the number of times.